NoneType Error

[Sam]

Hi, I'me trying to run a code but I'm getting an error that is 'NoneType' object has no attribute 'SetGeoTransform. I'm not sure what this means or how to fix it. My code is:

#Import OS
import os
import sys
os.environ['PATH'] = "C:/OSGeo4W64/bin" + ';' + os.environ['PATH']
sys.path.append('C:/OSGeo4W64/apps/Python27/Lib/site-packages/')
from osgeo import gdal
import numpy as np

#Define Filepath
filename = "C:\Users\masam066\Desktop\Files for python exercises\sfu.tif"

#Use GDAl to open() funtion to open the database
#Use if statement to check if the object ds exists and return error code '1' if it doesn't
ds = gdal.Open(filename)
if ds is None:
   sys.exit(1)

#Get info about the dataset
xsize = ds.RasterXSize
ysize = ds.RasterYSize
nbands = ds.RasterCount
projection = ds.GetProjection()
geotransform = ds.GetGeoTransform()

#Read the bands
bands = []
for i in range (nbands):
   bands.append(ds.GetRasterBand(i+1))
band1 = bands[0]
min = band1.GetMinimum()
band1.ComputeRasterMinMax(1)

#Read Data To Arrays
arrays = []
for i in range(nbands):
   arrays.append(bands[i].ReadAsArray(0, 0, xsize, ysize))

#Calculate pixel brightness
brightness = (arrays[0] + arrays[1] + arrays[2]) / 3


#Test whether band values are integes or floats
if(np.issubdtype(arrays[0].dtype, np.integer) is True):
   integerValues = True
else:
   integerValues = False

#Floating point division
brightness = (arrays[0] + arrays[1] + arrays[2]) / 3.0

#Writing results to raster files
filename = "C:\Users\masam066\Desktop\brightness.tif"
driver = gdal.GetDriverByName('GTiff')
dataset = driver.Create(filename, xsize, ysize, 1, gdal.GDT_Float32)
dataset.SetGeoTransform(geotransform)
dataset.SetProjection(projection)
band = dataset.GetRasterBand(1)
band.WriteArray(brightness)
dataset = None

It is the blue lines where PyScripter finds the error.

Moderator Larz60+: Added Python tags. Please do this in the future (see help, BBCODE)

[wavic]

Put print() after initializing dataset to see if it is set. Do the same after ds and geotransform initialisation.

[Sam]

So we added this like you suggested.

#Writing results to raster files
filename = "C:\Users\masam066\Desktop\brightness.tif"
driver = gdal.GetDriverByName('GTiff')
dataset = driver.Create(filename, xsize, ysize, 1, gdal.GDT_Float32)
print()
dataset.SetGeoTransform(geotransform)
print()
dataset.SetProjection(projection)
band = dataset.GetRasterBand(1)
band.WriteArray(brightness)
dataset = None

but recieved the same error

[ichabod801]

We need to see the output. What are the print statements printing? What exactly is the error you are getting?

Most likely, driver.Create() is returning None, not a dataset, and that's why you're getting the error. But we can't be sure of that without seeing the output and error message.

[Sam]

The print statements are not producing anything. And the error reads AttributeError: 'NoneType' object has no attribute 'SetGeoTransform'

[wavic]

I was meaning to print print(dataset), print(ds) and print(geotransform), not just to call print()

[Ofnuts]

NoneType is the type of the special None object. When you get "'NoneType' object has no attribute 'XXX'" it means you are trying to use the attribute XXX (or a method, since in Python, methods  behave like callable attributes) of the None object, usually because one of your variables contains None and not what you think.